The human brain stores, retrieves and and processes enormous amounts of information. This process is obviously critical to our daily--even monment to moment--existence. Disorders of storage and retrieval processes, whether classified as "functional" or "organic" are severely disabling. Korsakoff's disease, Alzheimer's disease, senility, and a wide variety of mental defects from mild to severe are reflections of various degrees of dysfunction of these processes. Localized injury to the brain can produce highly specific learning and memory disorders. An example of this is the classic amnesic syndrome seen with medial temporal lobe or medial diencephalic injury. The structures that are responsible for these symptoms have not been identified with certainty. These patients have enormous difficulty storing new information, although they can learn some kinds of things. This suggests that the machinery for storing and retrieving information is not a unitary mechanism and that the component parts of these mechanisms may be physically separable in the brain. Here we propose to use monkeys highly trained on a memory task and trace the mechanism by wehich their task is accomplished through the brain. We will use cold to make small reversible functional lesions and map the structures that are critical for the performance of this task. We will then use anatomical techniques to trace the connections of these areas to other parts of the brain.